Common Air Suspension Probelms

Air bag or air strut failure is usually caused by wet rust, due to old age, or moisture within the air system that damages it from the inside. Air ride suspension parts may fail because rubber dries out. Punctures to the air bag may be caused from debris on the road. With custom applications, improper installation may cause the air bags to rub against the vehicle's frame or other surrounding parts, damaging it. The over-extension of an air spring which is not sufficiently constrained by other suspension components, such as a shock absorber, may also lead to the premature failure of an air spring through the tearing of the flexible layers. Failure of an air spring may also result in complete immobilization of the vehicle, since the vehicle will rub against the ground or be too high to move. However, most modern automotive systems have overcome many of these problems.

Air line failure is a failure of the tubing which connects the air bags or struts to the rest of the air system, and is typically DOT-approved nylon air brake line. This usually occurs when the air lines, which must be routed to the air bags through the chassis of the vehicle, rub against a sharp edge of a chassis member or a moving suspension component, causing a hole to form. This mode of failure will typically take some time to occur after the initial installation of the system, as the integrity of a section of air line is compromised to the point of failure due to the rubbing and resultant abrasion of the material. An air line failure may also occur if a piece of road debris hits an air line and punctures or tears it, although this is unlikely to occur in normal road use. It does occur in harsh off-road conditions but it still not common if correctly installed.

Air fitting failure usually occurs when they are first fitted or very rarely in use. Cheap low quality components tend to be very unreliable. Air fittings are used to connect components such as bags, valves, and solenoids to the air line that transfers the air. They are screwed into the component and for the most part push-in or push-to-fit DOT line is then inserted into the fitting.

Compressor failure is primarily due to leaking air springs or air struts. The compressor will burn out trying to maintain the correct air pressure in a leaking air system. Compressor burnout may also be caused by moisture from within the air system coming into contact with its electronic parts. This is far more likely to occur with low specification compressors with insufficient duty cycle which are often purchased due to low cost. For redundancy in the system two compressors are often a better option.

In Dryer failure the dryer, which functions to remove moisture from the air system, eventually becomes saturated and unable to perform that function. This causes moisture to build up in the system and can result in damaged air springs and/or a burned out compressor.

ECAS problems

The ECAS computer can, using pre-programmed criteria to detect a fault, disable the system into "Hard Fault Mode" which lowers the vehicle to the suspension bump-stops, leaving it usable with radically reduced performance until repaired.

Many enthusiasts use diagnostic devices such as laptop and hand computers running specially developed software to clear spurious faults and avoid the need for repair. Some manipulate the sensors to set the vehicle to a particular ride height at all times by adjusting the lever ratio on the height-sensing devices, or a supplementary ECU to "fool" the system.

Leaks in the system, often due to main seal wear caused by excessive duty cycle, can cause premature compressor failure.

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